Search

Spent carbon cathode (SCC) is one of the major hazardous solid wastes generated during the overhaul of electrolysis cells in the aluminum production process. SCC is not only rich in carbon resources but also contains soluble fluoride and cyanide, which gives it both recycling value and significant leaching toxicity. In this study, we explore the properties, emissions, and disposal strategies for SCC. Pyrometallurgy involves processes such as vacuum distillation, molten salt roasting, and high-temperature roasting. Hydrometallurgy describes various methods used to separate valuable components from leachate and prepare products. Collaborative disposal plays a positive role in treating SCC alongside other solid wastes. High-value utilization provides an approach to make full use of high-purity carbon-based materials. Finally, we analyze and summarize future prospects for the disposal of SCC. This study aims to contribute to the large-scale treatment and resource utilization of SCC while promoting circular economy principles and green development initiatives. [ABSTRACT FROM AUTHOR]

Ni‐rich cathode material possesses a considerable theoretical capacity, yet achieving their full capacity potential remains challenging. Elevating its operation voltage is an effective approach, while the stability of Ni‐rich cathode material is relatively poor, which is limited by Li+/Ni2+ mixing. Herein, a strategy of cation/anion co‐doping is proposed for single‐crystal ultrahigh‐nickel cathode LiNi0.92Co0.04Mn0.04O2 operated at 4.5 V. The enhancement mechanism is explicitly revealed by in situ/ex situ tests and theory calculations. Specifically, Mo6+ and F− are introduced to construct an appropriate Li+/Ni2+ antisite defects structure at the particle surface, which can maintain the low‐defect Li+ layered channel inside the bulk simultaneously, inducing a stable access portal for Li+ transport from the cathode/electrolyte interface. More importantly, the Li+/Ni2+ antisite passivation layer on the surface can uphold the stability of Li‐layer and optimize the reactive behavior of Ni2+, thus boosting the interfacial stability and reducing the lattice mismatch. As a result, it can achieve high capacity (204 mAh g−1 at 1 C) and stable retention during long‐term high‐voltage measurements both in half‐cell (87.1% after 200 cycles) and full‐cell (91.9% after 400 cycles). This facile strategy provides a feasible technical reference for further exploiting the ultrahigh‐capacity of Ni‐rich cathode for commercial application. [ABSTRACT FROM AUTHOR]

Baking is the most costly and critical process in anode preparation, and the study from the microscopic scale is conducive to the optimisation of anode baking process. In this research, a hybrid simulation method of reactive force field molecular dynamics (ReaxFF-MD) and force-biased Monte Carlo (fbMC) was proposed to understand the interaction mechanism between coal tar pitch (CTP) and calcined petroleum coke (CPC) during kneading and baking processes, and to explore the optimal ratio of CTP from the molecular scale. Results showed that the CTP content of 14 wt.% was beneficial for anode production. The mechanism of anode coking behaviour at high temperatures was also analyzed. The carbonisation of CTP during high-temperature baking broke the carbon rings and formed straight chains, exposing active carbon atoms that can bond with the remaining layers. As the high-temperature simulation progresses, the carbon chains at the bonding sites became increasingly cyclized and aromatised, which made the layered structure of the baked block similar to that of graphite. The generation of various volatile hydrocarbons during the baking process was observed, namely CH4, C2H4, C2H2, C2H6, and C3H6. This work provides theoretical basis for process optimisation. [ABSTRACT FROM AUTHOR]